U.S. patent application number 10/663655 was filed with the patent office on 2004-11-04 for parallelism adjustment device.
Invention is credited to Chen, Chuan-Feng, Chen, Ming-Chi, Chung, Yong-Chen, Feng, Wen-Hung, Hsu, Chia-Chun, Lin, Chia-Hung.
Application Number | 20040219461 10/663655 |
Document ID | / |
Family ID | 32504972 |
Filed Date | 2004-11-04 |
United States Patent
Application |
20040219461 |
Kind Code |
A1 |
Chung, Yong-Chen ; et
al. |
November 4, 2004 |
Parallelism adjustment device
Abstract
A parallelism adjustment device applicable to nano-imprint
lithography has an imprint unit, a carrier unit, a parallelism
adjustment mechanism, and a driving source. The imprint unit has a
first molding plate and an imprinting mold mounted on the first
molding plate. The carrier unit has a second molding plate and a
substrate mounted on the second molding plate. The parallelism
adjustment mechanism has an enclosed resilient film and a fluid
filled therein, and is coupled to at least one of the first and
second molding plates. The driving source drives at least one of
the imprint unit and the carrier unit to form contact between the
mold and the moldable layer. The parallelism adjustment device is
pressed via the contact to adjust parallelism for the imprint mold
and the substrate and uniformly distributes the pressure between
the mold and the substrate, making the molding quality of
nano-imprint lithography significantly improved.
Inventors: |
Chung, Yong-Chen; (Hsinchu,
TW) ; Lin, Chia-Hung; (Hsinchu, TW) ; Chen,
Chuan-Feng; (Hsinchu, TW) ; Hsu, Chia-Chun;
(Hsinchu, TW) ; Feng, Wen-Hung; (Hsinchu, TW)
; Chen, Ming-Chi; (Hsinchu, TW) |
Correspondence
Address: |
RABIN & BERDO, P.C.
Suite 500
1101 14th Street N.W.
Washington
DC
20005
US
|
Family ID: |
32504972 |
Appl. No.: |
10/663655 |
Filed: |
September 17, 2003 |
Current U.S.
Class: |
430/311 |
Current CPC
Class: |
Y10S 425/019 20130101;
B29C 59/022 20130101; B82Y 10/00 20130101; B29C 33/303 20130101;
B82Y 40/00 20130101; B29C 2059/023 20130101; G03F 7/0002 20130101;
G03F 9/00 20130101 |
Class at
Publication: |
430/311 |
International
Class: |
G03C 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2003 |
TW |
092208079 |
Claims
What is claimed is:
1. A parallelism adjustment device applicable to nano-imprint
lithography, the device comprising: an imprint unit at least having
a first molding plate and an imprint mold mounted on the first
molding plate; a carrier unit at least having a second molding
plate and a substrate mounted on the second molding plate, wherein
a moldable layer is coated on the substrate; a parallelism
adjustment mechanism comprising an enclosed resilient film and a
fluid filled therein, wherein the parallelism adjustment mechanism
is coupled to at least one of the first and second molding plates;
and a driving source for driving at least one of the imprint unit
and the carrier unit, to allow the imprint mold to come into
contact with the moldable layer to perform imprinting, and to allow
the parallelism adjustment mechanism to be pressed via the contact
between the imprint mold and the moldable layer so as to adjust
parallelism for the imprint mold and the substrate with respect to
each other.
2. The parallelism adjustment device of claim 1, wherein the
parallelism adjustment mechanism is mounted between the first
molding plate and the imprint mold if the parallelism adjustment
mechanism is coupled to the first molding plate, so as to adjust
parallelism of the imprint mold when the parallelism adjustment
mechanism is pressed.
3. The parallelism adjustment device of claim 1, wherein the
parallelism adjustment mechanism is mounted between the second
molding plate and the substrate if the parallelism adjustment
mechanism is coupled to the second molding plate, so as to adjust
parallelism of the substrate when the parallelism adjustment
mechanism is pressed.
4. The parallelism adjustment device of claim 1, wherein the
resilient film of the parallelism adjustment mechanism is made of
one selected from the group consisting of rubber, plastic, other
polymeric materials, and flexible structures.
5. The parallelism adjustment device of claim 1, wherein the
parallelism adjustment mechanism further comprises a pressure
sensor for sensing a pressure applied to the parallelism adjustment
mechanism, so as to conduct instant pressure detection.
6. The parallelism adjustment device of claim 1, wherein a
positioning platform is coupled to at least one of the imprint unit
and the carrier unit, so as to facilitate positioning during
imprinting.
7. The parallelism adjustment device of claim 1, wherein the
driving source is a transmission unit composed of a linear motor
and a hydraulic cylinder, or composed of a server motor and a ball
screw rod.
8. The parallelism adjustment device of claim 1, wherein the
moldable layer is made of one selected from the group consisting of
a polymer, a metal, and a non-metal material.
9. The parallelism adjustment device of claim 1, wherein an
anti-adhesion layer is coated over the moldable layer and the
imprint mold respectively.
10. The parallelism adjustment device of claim 1, wherein the
imprint mold and the substrate are mounted on the imprint unit and
the carrier unit respectively by means of vacuum suction force,
mechanical force, or electromagnetic force.
11. The parallelism adjustment device of claim 1, wherein a heating
member is mounted on the imprint unit and the carrier unit to
achieve a pre-determined operation temperature during
imprinting.
12. The parallelism adjustment device of claim 1, wherein a cooling
member is mounted on the imprint unit and the carrier unit to
achieve a pre-determined reduced temperature after imprinting.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a parallelism adjustment
device applicable to nano-imprint lithography, and more
particularly, to a parallelism adjustment device that quickly
responds and easily operates.
BACKGROUND OF THE INVENTION
[0002] As the demand for producing smaller line widths of
integrated circuit increases, the use of conventional
photolithography process to define line widths that are smaller
than the wavelength of light for implementing nano-scale features
becomes increasingly difficult due to the diffraction of light.
Although subnano-scale features have also been studied, they still
cannot be implemented in mass production because the current
commercially available manufacturing equipment is not compatible
with the subnano-scale process. Therefore, a nano-imprint
lithography (NIL) has been developed to meet the requirements for
processing fine line widths, wherein the technology is adaptable to
low-cost mass production utilizing an enlarged feature-processing
area.
[0003] Nano-imprint lithography uses an imprint force to transfer
nano-scale features that are previously formed on a mold onto a
moldable layer applied on a substrate. The moldable layer is made
of a polymer such as polymethyl methacrylate (PMMA). After the
moldable layer is molded, a plurality of semiconductor processes
are subsequently applied to define a device with nano-scale line
widths. FIG. 3A to FIG. 3C schematically illustrate the process of
nano-imprint lithography, including heating, imprinting, cooling
and demolding steps. In the heating step illustrated in FIG. 3A, a
moldable layer 23 applied over a substrate 21 is heated to the
required operating temperature. During the imprinting step of FIG.
3B, a mold 11 with nano-scale features 13 are mounted on a first
molding plate 12, and a substrate 21 is mounted on a second molding
plate 26. The mold 11 moves towards the substrate 21 by means of a
driving source 14. When the mold 11 comes into contact with and
then presses the moldable layer on the substrate 21, the features
on the mold 11 are transferred onto the moldable layer 23. After
the moldable layer 23 cools down to an appropriate temperature, the
moldable layer 23 is demolding from the mold 11, as shown in FIG.
3C. Thereby, the nano-imprint lithography is accomplished.
[0004] For this recently developed technology, parallelism between
the mold and the substrate and uniformity of imprint force applied
during imprinting are crucial to the imprinting quality.
Specifically, since the mold and the substrate are respectively
mounted on the first and second molding plates, the uniformity of
the applied imprinting force is determined on the basis of the
pressure distribution of the first and second molding plates.
Therefore, if the pressure distribution on the molding plates and
the parallelism between the mold and the substrate are not
adequately controlled, the imprinting precision is adversely
affected, and the nano-scale features on the mold or even the
substrate will be damaged. Compared to conventional hot embossing,
the nano-imprint lithography requires higher imprint precision,
higher parallelism and uniformity of imprint pressure. The current
processing apparatus does not meet the high requirements of
nano-imprint lithography.
[0005] FIG. 4 shows an apparatus for molding microsystem structures
disclosed in U.S. Pat. No. 5,993,189. A mold 63 having nano-scale
features are mounted on an upper carrier 61, while a substrate 64
is mounted on a lower carrier 62. The lower carrier 62 moves upward
under guide 65 to perform imprinting. In this apparatus, no
parallelism adjustment device is provided. Therefore, the
parallelism between the mold 63 and the substrate 64 is not ensured
due to possible manufacturing errors or an improper assembly of
components such as the mold and guide.
[0006] FIG. 5 shows of a molding apparatus disclosed in PCT patent
No. WO 0169317. An imprint mold 71 and a substrate 72 are
respectively connected to individual oil hydraulic cylinders 73,
74. The mold 71 comes into contact with the substrate 72 by means
of the cylinder 73 to effect the imprint process. With the limited
resilience of an O-ring 76 installed inside the oil hydraulic
cylinder 75, the mold 71 and the substrate 72 are subject to a
shift in parallelism adjustment before contacting each other. The
use of the oil hydraulic cylinders 75, 77 makes the whole structure
and operation complex. Furthermore, the oil hydraulic system has
disadvantages such as poor control response.
[0007] FIG. 6 shows the fluid pressure imprint lithography
disclosed in U.S. Pat. No. 6,482,742, which has problems similar to
the above. An elastic sealing member 81 seals a mold 82 and a
substrate 83 stacked together. After the stack is placed in a
pressure chamber 84, a fluid is charged in the pressure chamber 84
through an inlet 85. Thus, the imprint process is achieved by the
fluid pressure. Thereafter, the fluid is drained through an outlet
86 and the substrate 83 is removed. The sealing and imprinting of
this apparatus are complex and time-consuming, which is unfavorable
to efficient mass production. Furthermore, since the processing of
the mold 82 and the substrate 83 requires stacking, sealing,
transferring into the pressure chamber, and a pressure increasing
and decreasing steps, it is difficult to achieve precision
alignment due to the combined variability of all the processing
steps.
[0008] FIG. 7 shows a molding apparatus disclosed in PCT patent WO
0142858. A pressure chamber 92 is mounted under the substrate 91. A
resilient film 93 is established between the pressure chamber 92
and the substrate 91. A highly pressurized liquid is charged in the
pressure chamber 92 to perform the imprint process. This method is
complex and requires generating high pressure, which consumes a lot
of energy and may cause environmental pollution.
[0009] Therefore, there is a need for a parallelism adjustment
device suitable for nano-imprint lithography providing reduced
manufacturing and assembly errors, uniformity of imprint pressure,
and improved nano-imprint quality. Furthermore, the parallelism
adjustment device should have a simple construction that can
respond quickly and easily, and that can be manufactured and
operated at low cost.
SUMMARY OF THE INVENTION
[0010] A primary objective of the invention is to provide a
parallelism adjustment device that provides a highly uniform
imprint pressure in the nano-imprint lithography.
[0011] Another objective of the invention is to provide a
parallelism adjustment device that does not cause damage to molds
and substrates.
[0012] Still another objective of the invention is to provide a
parallelism adjustment device that has a simple construction and
can be manufactured at low cost.
[0013] A further objective of the invention is to provide a
parallelism adjustment device which responds instantly.
[0014] A further objective of the invention is to provide a
parallelism adjustment device that does not require preliminary
preparation and can be operated easily.
[0015] In accordance with the above and other objectives, the
parallelism adjustment device applicable to nano-imprint
lithography of the invention includes an imprint unit, a carrier
unit, a parallelism adjustment mechanism, and a driving source. The
imprint unit is at least provided with a first molding plate and an
imprinting mold mounted on the first molding plate. The carrier
unit is at least provided with a second molding plate and a
substrate mounted on the second molding plate. The parallelism
adjustment mechanism includes an enclosed resilient film and a
fluid filled therein, and is attached on at least one of the first
and second molding plates. The driving source is used to drive the
imprint unit and the carrier unit to allow a contact to be formed
between the mold and the moldable layer, and to allow parallelism
adjustment for the mold and the substrate.
[0016] And while the parallelism adjustment mechanism has to be
secured between the first molding plate and the imprinting mold if
the parallelism adjustment mechanism is to be mounted on the first
molding plate. The parallelism has to be secured between the second
molding plate and the substrate if the parallelism mechanism is to
be mounted on the second molding plate. As a result, the
parallelism between the imprinting mold and the substrate is
adjusted when the pressured is applied to the parallelism
adjustment mechanism. The resilient film of the parallelism
adjustment mechanism described above may be made of polymer
materials, such as rubber and plastic or other flexible structures.
The fluid that fills the resilient film may include any liquids or
gases.
[0017] Furthermore, the parallelism adjustment mechanism includes a
pressure sensor for sensing the applied pressure, so as to monitor
the pressure instantly. With a pressure-time control curve
previously established, the nano-imprinting process can be
controlled. Meanwhile, the imprint unit and the carrier unit may be
coupled to an alignment platform with a large area, so as to
enhance the horizontal alignment in the imprinting process.
[0018] Accordingly, the parallelism adjustment device is proposed
to achieve objectives such as high level of freedom, instant
responsiveness, and no harm done to the mold and the substrate.
After the imprint unit makes a contact with the carrier unit,
non-uniform pressure distribution that occurs during the imprinting
process is offset with the pressure exerted by the enclosed
resilient membrane and the fluid. That is, when both the imprint
unit and the carrier unit suffer from the poor parallelism, the
parallelism may be adjusted passively via instant deformation of
the resilient membrane, while such adjustment is can be made at
wider angles without limited by the direction. With the property of
the fluid, the pressure is evenly applied to the substrate of the
carrier unit, in order to satisfy efficient and high quality
imprinting requirements. And instead of placing in the closed
chamber, the imprint unit and the carrier unit are operated
independently, so complex preparations prior to the imprinting can
be omitted. Accordingly, the present invention has a simple
construction manufactured with a low cost, and the commercial
demand is met for mass production at a rapid rate.
[0019] To provide a further understanding of the invention, the
following detailed description illustrates embodiments and examples
of the invention, this detailed description being provided only for
illustration of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The drawings included herein provide a further understanding
of the invention. A brief description of the drawings is as
follows:
[0021] FIG. 1 is a schematic view of a parallelism adjustment
device according to a first embodiment of the invention;
[0022] FIG. 2 is a schematic view of a parallelism adjustment
device according to a second embodiment of the invention;
[0023] FIG. 3A through to FIG. 3C (PRIOR ART) are schematic views
illustrating the nano-imprint lithography process;
[0024] FIG. 4 (PRIOR ART) is a schematic view of a nano-imprint
device disclosed in U.S. Pat. No. 5,993,189;
[0025] FIG. 5 (PRIOR ART) is a schematic view of a nano-imprint
device disclosed in PCT Patent No. WO 0169317;
[0026] FIG. 6 (PRIOR ART) is a schematic view of a nano-imprint
device disclosed in U.S. Pat. No. 6,482,742; and
[0027] FIG. 7 (PRIOR ART) is a schematic view of a nano-imprint
device disclosed in PCT Patent No. WO 0142858.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Wherever possible in the following description, like
reference numerals will refer to like elements and parts unless
otherwise stated.
[0029] FIG. 1 depicts a parallelism adjustment device 1 applicable
to nano-imprint lithography (NIL) according to the first embodiment
of the invention. The parallelism adjustment device 1 includes an
imprint unit 10 consisting of a mold 11, a first molding plate 12
and a driving source 14. The imprint unit 10 moves toward a carrier
unit 20 by means of a plurality of the guiding poles 15. At least
one nano-scale feature 13 to be imprinted is previously formed on
the mold 11. The carrier unit 20 includes a second molding plate 26
mounted on a positioning platform 31. A resilient film 24 capable
of withstanding high pressure is formed inside the second molding
plate 26, and hermetically enclosed therein. A fluid 25 fills up
the resilient film 24 to form a parallelism adjustment mechanism
27. A substrate 21 coated with a moldable layer 23 is mounted on
the carrier unit 20 via vacuum suction of a suction plate 22, such
that the moldable layer faces opposite to the nano-scale features
13 of the mold 11.
[0030] The suction plate 22 has a pinhole (not shown). The suction
plate 22 and the substrate 21 are placed together on the resilient
film 26. Then, the substrate 21 is aligned with the mold 11 by
means of the positioning platform 31 with horizontal positioning
ability to increase precision of nano-imprint lithography. A
plurality of heaters 51 is further mounted on the first molding
plate 12. The heaters 51, preferably rapid heating units (not
shown) mounted between the substrate 21 and the mold 11, increase
the temperature of the moldable layer 23 up to a predetermined
operating temperature for the imprint lithography. A mold cooling
member 41 is also mounted on the first molding plate 12, while a
substrate cooling member 42 is mounted on the suction plate 22.
These cooling members 41, 42 serve to cool the mold 11 and the
substrate 21 for mold release after the imprint lithography is
completed.
[0031] In the parallelism adjustment device 1, a pressure sensor 55
is further mounted on the parallelism adjustment mechanism 27 to
measure the pressure applied when the mold 11 comes into contact
with the moldable layer 23, thereby monitoring the pressure during
the imprint lithography. This is achieved via a predetermined
pressure-time operation curve. When the pressure applied to the
parallelism adjustment mechanism 27 is increased to a particular
value and the mold 11 makes the contact with the moldable layer 23,
the pressure is maintained at that value for several seconds.
Thereafter, the mold 11 is removed to complete imprint lithography.
The relationship between pressure and time can be obtained from
experimental tests, depending on the imprint material and the
desired imprint precision. The location for the pressure sensor 55
is not limited to that shown in FIG. 1. The pressure sensor 55 can
be mounted anywhere as long as it can detect the pressure variation
during imprint lithography.
[0032] The resilient film 24 in the parallelism adjustment
mechanism 27 is made of a polymer such as rubber or plastic, or
other flexible materials. The fluid 25 can be of any type of liquid
or gas. The moldable layer 23 can be a polymeric material, or other
moldable metallic or non-metallic material. The mold 11 and the
substrate 21 are respectively positioned on the first and second
molding plates 12, 26 by vacuum suction force, mechanical force, or
electromagnetic force. Furthermore, the driving source 14 is
constructed from, for example, a combination of a linear motor and
a hydraulic cylinder, or a combination of a server motor, a ball
screw rod, and other components.
[0033] The imprint lithography process performed by using the
parallelism adjustment device 1 of the invention includes the
following steps. The heaters 51 mounted on the first molding plate
12 and the rapid heating unit formed between the substrate 21 and
the mold 11 (not shown), if any, increase the temperature of the
moldable layer 23 up to an imprint operating temperature. The
driving source 14 of the imprint unit 10 drives the first molding
plate 12 and the mold 11 thereon to move toward the carrier unit 20
by means of the guiding poles 15. When the imprint unit 10 comes
into contact with the carrier unit 20, one or more nano-scale
features 13 on the mold 11 are pressed and then transferred to the
moldable layer 23 on the substrate 21. Since the resilient film 24
of the carrier unit 20 is flexible, a parallelism adjustment is
conducted passively according to the direction where imprint unit
10 exerts the pressure to achieve an ideal parallelism as the mold
11 makes the contact with the substrate 21. Therefore, the
parallelism requirement is satisfied during the imprinting process.
The fluid 25 in the resilient film 24 keeps the substrate 21 at a
pressure as uniform as possible. When the driving source 14 slowly
applies the pressure, the pressure sensor 55 on the resilient film
24 monitors the applied pressure to provide feedback to control the
imprint force based on the predetermined pressure curve. After the
imprint lithography is completed, a mold cooling member 41 of the
first mold 12 and a substrate cooling member 42 of the suction
plate 22, respectively, cool the mold 11 and the substrate 21 down
to appropriate temperatures. Then, the driving source 14 drives the
imprint unit 10 to release the moldable layer 23 from the mold 11
so as to complete the imprinting process. Furthermore, a highly
evaporable anti-adhesion layer (not shown) may be coated between
the mold 11 and the substrate 21, before the imprint lithography is
performed, to facilitate the release of the moldable layer 23.
[0034] FIG. 2 is a schematic view of a parallelism adjustment
device according to a second embodiment of the invention. The
parallelism adjustment device in this embodiment is similar to that
described in the first embodiment of the invention, except that the
parallelism adjustment mechanism 27 is mounted on the imprint unit
10 to achieve the same parallelism adjustment. According to the
design, the imprint unit 10 is provided with a positioning plate
28. And the resilient film 24 is located between the positioning
plate 28 and the first molding plate 12, such that the mold 11 of
the imprint unit 10 is adjusted via the force of contact formed
between the mold 11 and the substrate 21 and flexibility of the
resilient membrane 24 to achieve parallelism and uniform pressure
distribution. Since the components are arranged in a similar way to
that described in the first embodiment, the detail is omitted
herein.
[0035] In a further embodiment (not shown), the resilient film 24
can be mounted both on the imprint unit 10 and the carrier unit 20.
That is, resilient film 24 is mounted between the positioning plate
28 and the first molding plate 12, and between the second molding
plate 26 and the suction plate 22. Moreover, construction of the
invention is not limited to the above description. For example, the
substrate 21 may be mounted on the imprint unit 10 and the mold 11
may be mounted on the carrier unit 20. Meanwhile, a positioning
platform 31 that enhances positioning of the mold 11 of the imprint
unit 10 may be further provided to increase precision of
positioning in the imprint lithography.
[0036] As described above, the parallelism adjustment device
applicable to the nano-imprint lithography according to the
invention significantly mitigate the problems associated with the
prior art. The resilient film provides parallelism adjustment and
the fluid therein provides uniform pressure distribution without
the need of any additional driving sources for parallelism
adjustment. Thereby, processing and assembly errors can be reduced,
and problems caused from vibration of the driving source are
prevented. Furthermore, the invention provides advantages, such as
simple construction, low production cost, rapid response and low
operation complexity.
[0037] It should be apparent to those skilled in the art that the
above description is only illustrative of specific embodiments and
examples of the invention. The invention should therefore cover
various modifications and variations made to the herein-described
structure and operations of the invention, provided they fall
within the scope of the invention as defined in the following
appended claims.
* * * * *